BREMERTON —Attack submarine USS Seawolf returned to sea after a 31-month, $280 million maintenance and modernizing stop at Puget Sound Naval Shipyard and Intermediate Maintenance Facility. It completed sea trials last week to ensure its systems were working properly and the boat was combat-ready. Now, the crew will go through a series of training and certification periods to improve their war-fighting ability.

"We are ecstatic to be at sea again, and Seawolf is even more capable and effective than at any time in her 15 years of service," Cmdr. Dan Packer, Seawolf's commanding officer, said in a news release.

The Seawolf was commissioned in July 1997, the first of what was planned to be 29 boats of its class. Their main mission was to destroy Soviet ballistic submarines before they could attack American targets. Though it was the quietest submarine ever built, it also was the most expensive. With the Cold War over, production was stopped after three boats, and the Navy switched to building smaller, cheaper Virginia-class submarines.

The other two Seawolfs are the USS Connecticut and USS Jimmy Carter.

They're homeported at Bremerton. The Navy says they're the fastest, quietest, deepest-diving and most heavily armed fast attack submarines in the fleet. The Navy officially lists the speed at 25-plus knots and the operating depth at "greater than 800 feet." The real numbers are secret. The subs can carry 50 Tomahawk cruise missiles or 50 Harpoon anti-ship missiles or 50 torpedoes or up to 100 mines.

The Jimmy Carter, which was modified to conduct secret operations such as transporting SEALS and undersea recovery, has been assigned to Bangor since November 2005.

The other two transferred from Groton, Conn., in 2007 as part of the Navy's shift of 60 percent of its firepower to the Pacific Ocean. The Seawolf arrived July 22, 2007; the Connecticut, after a deployment, Jan. 29, 2008.

All three could eventually wind up at Bangor.

In the environmental assessment for an explosives handling wharf, dated January 2012, is a section called "cumulative impacts." It lists past, present and reasonably foreseeable future projects in Hood Canal. Included is a Bangor service pier extension to homeport two more Seawolf-class submarines. It describes a 33,000-square-foot extension, new pier services and compressor building on the existing pier, upland maintenance support facility and 421-car parking lot.

Puget Sound Naval Bases Association annually treks to Washington, D.C., to encourage key politicians and Navy brass to support local Navy efforts. The pier was among issues it presented six weeks ago. The group says the submarines' squadron, Submarine Development Squadron 5, is working to get all the boats at Bangor. It would be less expensive and more efficient to centralize operations and training there.

Yep, that's a lot of money! And 31 months is a lot of time for an overhaul. I know that Seawolf had a lot of problems with the tolerances being so tight on some items (for silencing purposes) that there were chronic mechanical problems (binding of parts, etc.). It's possible that some of those issues were addressed. I am also guessing that the reactor core may have been swapped out as well at roughly the 15 year point, as she has the S6W reactor, not the new "life of hull core" found in the Virginia S9G. If you recore, you are looking at cutting the hull open, rigging to remove "hot" fuel from the reactor and installing new fuel bundles. That is never cheap.

So they would give her a new S9G? I just assumed enough stuff would be different between the two that it wouldn't be practical to do something like that. Interesting

No, they would not. They would replace the depleted S6W core (recoring) with new fuel bundles. It's the same reactor, it just has new enriched uranium fuel (along with other elements to modulate neutron production and ameliorate "core poisons" over time). The point was that the S6W is not a "life of hull" core; the S9G is. So, while the Seawolf class boats will need to be recored (probably around the 12-14 year period) the Virginias have a core (S9G) that will last as long as the hull.

The cost of the over haul hast many items. First if the hull has to be cut to add or remove equipment and then re-weld there are high cost with this. The weld can not have any flaws at all in it, this means no air bubbles at all. when the welds are done they do some into the hull cut and then they have to do Radio Photography after to make sure all is good before they can weld more. Second is the cost of the equipment which all has to be sub safe items. Also if any of the sound silencing items have to be replace this can add up quickly as well. Also with the hull opening being done they then have to replace all of the rubber hull coating that was removed as well. This can cost a small fortune do to the newer way of doing the rubber coating unlike what it was when I served. We had rubber tiles that were used were as today they do a solid cast all the way around the sub to make it a solid item. Subs are high maintance but are worth every penny. Just ask any one who has served on a sub.

Thanks, Duane for your comments. Bottom line is that if you need to get to the reactor for major work, you are cutting into the hull and incurring serious costs to bring the hull and the other components back to their original state. The welding alone has to be done where the hull is pre-heated and layers of weld built up to the full hull thickness over weeks. No voids (hence the need for radiography of the hull) must be present in the welds. On top of all that, Seawolf has HY-100 steel, even more finicky to weld than HY-80. During Seawolf construction, EB had to go back and redo a significant number of the welds because they didn't pass inspection. HY-100 was much more difficult to get it right! As Duane points out, there is SubSafe standards to meet. The hull is as strong as its weakest weld.